netsurf/desktop/browser.c

/*
 * Copyright 2003 Phil Mellor <monkeyson@users.sourceforge.net>
 * Copyright 2006 James Bursa <bursa@users.sourceforge.net>
 * Copyright 2004 Andrew Timmins <atimmins@blueyonder.co.uk>
 * Copyright 2004 John Tytgat <joty@netsurf-browser.org>
 * Copyright 2006 Richard Wilson <info@tinct.net>
 * Copyright 2008 Michael Drake <tlsa@netsurf-browser.org>
 * Copyright 2009 Paul Blokus <paul_pl@users.sourceforge.net>
 *
 * This file is part of NetSurf, http://www.netsurf-browser.org/
 *
 * NetSurf is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * NetSurf is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * \file
 *
 * Browser window creation and manipulation implementation.
 */

#include "utils/config.h"

#include <assert.h>
#include <limits.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <math.h>
#include <nsutils/time.h>

#include "utils/corestrings.h"
#include "utils/log.h"
#include "utils/messages.h"
#include "utils/nsurl.h"
#include "utils/utils.h"
#include "utils/utf8.h"
#include "utils/nsoption.h"
#include "netsurf/misc.h"
#include "netsurf/window.h"
#include "netsurf/content.h"
#include "netsurf/plotters.h"
#include "content/content_debug.h"
#include "content/fetch.h"
#include "content/hlcache.h"
#include "content/urldb.h"
#include "css/utils.h"
#include "render/form_internal.h"
#include "render/html.h"
#include "render/box.h"
#include "javascript/js.h"

#include "desktop/browser_history.h"
#include "desktop/browser_private.h"
#include "desktop/download.h"
#include "desktop/frames.h"
#include "desktop/global_history.h"
#include "desktop/hotlist.h"
#include "desktop/knockout.h"
#include "desktop/scrollbar.h"
#include "desktop/selection.h"
#include "desktop/theme.h"
#include "desktop/gui_internal.h"
#include "desktop/textinput.h"


/** maximum frame depth */
#define FRAME_DEPTH 8


/**
 * Get position of scrollbar widget within browser window.
 *
 * \param  bw		The browser window
 * \param  horizontal	Whether to get position of horizontal scrollbar
 * \param  x		Updated to x-coord of top left of scrollbar widget
 * \param  y		Updated to y-coord of top left of scrollbar widget
 */

static inline void browser_window_get_scrollbar_pos(struct browser_window *bw,
		bool horizontal, int *x, int *y)
{
	if (horizontal) {
		*x = 0;
		*y = bw->height - SCROLLBAR_WIDTH;
	} else {
		*x = bw->width - SCROLLBAR_WIDTH;
		*y = 0;
	}
}


/**
 * Get browser window scrollbar widget length
 *
 * \param  bw		The browser window
 * \param  horizontal	Whether to get length of horizontal scrollbar
 * \return the scrollbar's length
 */
static inline int browser_window_get_scrollbar_len(struct browser_window *bw,
		bool horizontal)
{
	if (horizontal)
		return bw->width - (bw->scroll_y != NULL ? SCROLLBAR_WIDTH : 0);
	else
		return bw->height;
}


/* exported interface, documented in browser.h */
nserror
browser_window_get_name(struct browser_window *bw, const char **out_name)
{
	assert(bw != NULL);

	*out_name = bw->name;

	return NSERROR_OK;
}

/* exported interface, documented in browser.h */
nserror 
browser_window_set_name(struct browser_window *bw, const char *name)
{
	char *nname = NULL;

	assert(bw != NULL);

	if (name != NULL) {
		nname = strdup(name);
		if (nname == NULL) {
			return NSERROR_NOMEM;
		}
	}
	
	if (bw->name != NULL) {
		free(bw->name);
	}

	bw->name = nname;

	return NSERROR_OK;
}

/* exported interface, documented in browser.h */
bool browser_window_redraw(struct browser_window *bw, int x, int y,
		const struct rect *clip, const struct redraw_context *ctx)
{
	struct redraw_context new_ctx = *ctx;
	int width = 0;
	int height = 0;
	bool plot_ok = true;
	content_type content_type;
	struct content_redraw_data data;
	struct rect content_clip;

	if (bw == NULL) {
		LOG("NULL browser window");
		return false;
	}

	if (bw->current_content == NULL && bw->children == NULL) {
		/* Browser window has no content, render blank fill */
		ctx->plot->clip(clip);
		return ctx->plot->rectangle(clip->x0, clip->y0,
				clip->x1, clip->y1,
				plot_style_fill_white);
	}

	/* Browser window has content OR children (frames) */

	if ((bw->window != NULL) &&
	    (ctx->plot->option_knockout)) {
		/* Root browser window: start knockout */
		knockout_plot_start(ctx, &new_ctx);
	}

	new_ctx.plot->clip(clip);

	/* Handle redraw of any browser window children */
	if (bw->children) {
		struct browser_window *child;
		int cur_child;
		int children = bw->rows * bw->cols;

		if (bw->window != NULL)
			/* Root browser window; start with blank fill */
			plot_ok &= new_ctx.plot->rectangle(clip->x0, clip->y0,
					clip->x1, clip->y1,
					plot_style_fill_white);

		/* Loop through all children of bw */
		for (cur_child = 0; cur_child < children; cur_child++) {
			/* Set current child */
			child = &bw->children[cur_child];

			/* Get frame edge box in global coordinates */
			content_clip.x0 = (x + child->x) * child->scale;
			content_clip.y0 = (y + child->y) * child->scale;
			content_clip.x1 = content_clip.x0 +
					child->width * child->scale;
			content_clip.y1 = content_clip.y0 +
					child->height * child->scale;

			/* Intersect it with clip rectangle */
			if (content_clip.x0 < clip->x0)
				content_clip.x0 = clip->x0;
			if (content_clip.y0 < clip->y0)
				content_clip.y0 = clip->y0;
			if (clip->x1 < content_clip.x1)
				content_clip.x1 = clip->x1;
			if (clip->y1 < content_clip.y1)
				content_clip.y1 = clip->y1;

			/* Skip this frame if it lies outside clip rectangle */
			if (content_clip.x0 >= content_clip.x1 ||
					content_clip.y0 >= content_clip.y1)
				continue;

			/* Redraw frame */
			plot_ok &= browser_window_redraw(child,
					x + child->x, y + child->y,
					&content_clip, &new_ctx);
		}

		/* Nothing else to redraw for browser windows with children;
		 * cleanup and return */
		if (bw->window != NULL && ctx->plot->option_knockout) {
			/* Root browser window: knockout end */
			knockout_plot_end();
		}

		return plot_ok;
	}

	/* Handle browser windows with content to redraw */

	content_type = content_get_type(bw->current_content);
	if (content_type != CONTENT_HTML && content_type != CONTENT_TEXTPLAIN) {
		/* Set render area according to scale */
		width = content_get_width(bw->current_content) * bw->scale;
		height = content_get_height(bw->current_content) * bw->scale;

		/* Non-HTML may not fill viewport to extents, so plot white
		 * background fill */
		plot_ok &= new_ctx.plot->rectangle(clip->x0, clip->y0,
				clip->x1, clip->y1, plot_style_fill_white);
	}

	/* Set up content redraw data */
	data.x = x - scrollbar_get_offset(bw->scroll_x);
	data.y = y - scrollbar_get_offset(bw->scroll_y);
	data.width = width;
	data.height = height;

	data.background_colour = 0xFFFFFF;
	data.scale = bw->scale;
	data.repeat_x = false;
	data.repeat_y = false;

	content_clip = *clip;

	if (!bw->window) {
		int x0 = x * bw->scale;
		int y0 = y * bw->scale;
		int x1 = (x + bw->width - ((bw->scroll_y != NULL) ?
				SCROLLBAR_WIDTH : 0)) * bw->scale;
		int y1 = (y + bw->height - ((bw->scroll_x != NULL) ?
				SCROLLBAR_WIDTH : 0)) * bw->scale;

		if (content_clip.x0 < x0) content_clip.x0 = x0;
		if (content_clip.y0 < y0) content_clip.y0 = y0;
		if (x1 < content_clip.x1) content_clip.x1 = x1;
		if (y1 < content_clip.y1) content_clip.y1 = y1;
	}

	/* Render the content */
	plot_ok &= content_redraw(bw->current_content, &data,
			&content_clip, &new_ctx);

	/* Back to full clip rect */
	new_ctx.plot->clip(clip);

	if (!bw->window) {
		/* Render scrollbars */
		int off_x, off_y;
		if (bw->scroll_x != NULL) {
			browser_window_get_scrollbar_pos(bw, true,
					&off_x, &off_y);
			plot_ok &= scrollbar_redraw(bw->scroll_x,
					x + off_x, y + off_y, clip,
					bw->scale, &new_ctx);
		}
		if (bw->scroll_y != NULL) {
			browser_window_get_scrollbar_pos(bw, false,
					&off_x, &off_y);
			plot_ok &= scrollbar_redraw(bw->scroll_y,
					x + off_x, y + off_y, clip,
					bw->scale, &new_ctx);
		}
	}

	if (bw->window != NULL && ctx->plot->option_knockout) {
		/* Root browser window: end knockout */
		knockout_plot_end();
	}

	return plot_ok;
}

/* exported interface, documented in browser.h */
bool browser_window_redraw_ready(struct browser_window *bw)
{
	if (bw == NULL) {
		LOG("NULL browser window");
		return false;
	} else if (bw->current_content != NULL) {
		/* Can't render locked contents */
		return !content_is_locked(bw->current_content);
	}

	return true;
}

/* exported interface, documented in browser_private.h */
void browser_window_update_extent(struct browser_window *bw)
{
	if (bw->window != NULL)
		/* Front end window */
		guit->window->update_extent(bw->window);
	else
		/* Core-managed browser window */
		browser_window_handle_scrollbars(bw);
}

/* exported interface, documented in browser.h */
void browser_window_get_position(struct browser_window *bw, bool root,
		int *pos_x, int *pos_y)
{
	*pos_x = 0;
	*pos_y = 0;

	assert(bw != NULL);

	while (bw) {
		switch (bw->browser_window_type) {

		case BROWSER_WINDOW_FRAMESET:
			*pos_x += bw->x * bw->scale;
			*pos_y += bw->y * bw->scale;
			break;

		case BROWSER_WINDOW_NORMAL:
			/* There is no offset to the root browser window */
			break;

		case BROWSER_WINDOW_FRAME:
			/* Iframe and Frame handling is identical;
			 * fall though */
		case BROWSER_WINDOW_IFRAME:
			*pos_x += (bw->x - scrollbar_get_offset(bw->scroll_x)) *
					bw->scale;
			*pos_y += (bw->y - scrollbar_get_offset(bw->scroll_y)) *
					bw->scale;
			break;
		}

		bw = bw->parent;

		if (!root) {
			/* return if we just wanted the position in the parent
			 * browser window. */
			return;
		}
	}
}

/* exported interface, documented in browser.h */
void browser_window_set_position(struct browser_window *bw, int x, int y)
{
	assert(bw != NULL);

	if (bw->window == NULL) {
		/* Core managed browser window */
		bw->x = x;
		bw->y = y;
	} else {
		LOG("Asked to set position of front end window.");
		assert(0);
	}
}

/* exported interface, documented in browser.h */
void browser_window_set_drag_type(struct browser_window *bw,
		browser_drag_type type, const struct rect *rect)
{
	struct browser_window *top_bw = browser_window_get_root(bw);
	gui_drag_type gtype;

	bw->drag_type = type;

	if (type == DRAGGING_NONE) {
		top_bw->drag_window = NULL;
	} else {
		top_bw->drag_window = bw;

		switch (type) {
		case DRAGGING_SELECTION:
			/* TODO: tell front end */
			return;
		case DRAGGING_SCR_X:
		case DRAGGING_SCR_Y:
		case DRAGGING_CONTENT_SCROLLBAR:
			gtype = GDRAGGING_SCROLLBAR;
			break;
		default:
			gtype = GDRAGGING_OTHER;
			break;
		}

		guit->window->drag_start(top_bw->window, gtype, rect);
	}
}

/* exported interface, documented in browser.h */
browser_drag_type browser_window_get_drag_type(struct browser_window *bw)
{
	return bw->drag_type;
}

/* exported interface, documented in browser.h */
struct browser_window * browser_window_get_root(struct browser_window *bw)
{
	while (bw && bw->parent) {
		bw = bw->parent;
	}
	return bw;
}

/* exported interface, documented in browser.h */
browser_editor_flags browser_window_get_editor_flags(struct browser_window *bw)
{
	browser_editor_flags ed_flags = BW_EDITOR_NONE;
	assert(bw->window);
	assert(bw->parent == NULL);

	if (bw->selection.bw != NULL) {
		ed_flags |= BW_EDITOR_CAN_COPY;

		if (!bw->selection.read_only)
			ed_flags |= BW_EDITOR_CAN_CUT;
	}

	if (bw->can_edit)
		ed_flags |= BW_EDITOR_CAN_PASTE;

	return ed_flags;
}

/* exported interface, documented in browser.h */
bool browser_window_can_select(struct browser_window *bw)
{
	if (bw == NULL || bw->current_content == NULL)
		return false;

	/* TODO: We shouldn't have to know about specific content types
	 *       here.  There should be a content_is_selectable() call. */
	if (content_get_type(bw->current_content) != CONTENT_HTML &&
			content_get_type(bw->current_content) !=
			CONTENT_TEXTPLAIN)
		return false;

	return true;
}

/* exported interface, documented in browser.h */
char * browser_window_get_selection(struct browser_window *bw)
{
	assert(bw->window);
	assert(bw->parent == NULL);

	if (bw->selection.bw == NULL ||
			bw->selection.bw->current_content == NULL)
		return NULL;

	return content_get_selection(bw->selection.bw->current_content);
}

/* exported interface, documented in netsurf/browser_window.h */
bool browser_window_can_search(struct browser_window *bw)
{
	if (bw == NULL || bw->current_content == NULL)
		return false;

	/** \todo We shouldn't have to know about specific content
	 * types here. There should be a content_is_searchable() call.
	 */
	if ((content_get_type(bw->current_content) != CONTENT_HTML) &&
	    (content_get_type(bw->current_content) != CONTENT_TEXTPLAIN)) {
		return false;
	}

	return true;
}


/* exported interface, documented in netsurf/browser_window.h */
bool browser_window_is_frameset(struct browser_window *bw)
{
	return (bw->children != NULL);
}


/* exported interface, documented in netsurf/browser_window.h */
nserror browser_window_get_scrollbar_type(struct browser_window *bw,
		browser_scrolling *h, browser_scrolling *v)
{
	*h = bw->scrolling;
	*v = bw->scrolling;

	return NSERROR_OK;
}

/**
 * Set or remove a selection.
 *
 * \param bw		browser window with selection
 * \param selection	true if bw has a selection, false if removing selection
 * \param read_only	true iff selection is read only (e.g. can't cut it)
 */
static void browser_window_set_selection(struct browser_window *bw,
		bool selection, bool read_only)
{
	struct browser_window *top;

	assert(bw != NULL);

	top = browser_window_get_root(bw);

	assert(top != NULL);

	if (bw != top->selection.bw && top->selection.bw != NULL &&
			top->selection.bw->current_content != NULL) {
		/* clear old selection */
		content_clear_selection(top->selection.bw->current_content);
	}

	if (selection) {
		top->selection.bw = bw;
	} else {
		top->selection.bw = NULL;
	}

	top->selection.read_only = read_only;
}

/* exported interface, documented in browser.h */
void browser_window_scroll_visible(struct browser_window *bw,
		const struct rect *rect)
{
	assert(bw != NULL);

	if (bw->window != NULL) {
		/* Front end window */
		guit->window->scroll_visible(bw->window,
				rect->x0, rect->y0, rect->x1, rect->y1);
	} else {
		/* Core managed browser window */
		if (bw->scroll_x != NULL)
			scrollbar_set(bw->scroll_x, rect->x0, false);
		if (bw->scroll_y != NULL)
			scrollbar_set(bw->scroll_y, rect->y0, false);
	}
}

/* exported interface, documented in browser.h */
void browser_window_set_scroll(struct browser_window *bw, int x, int y)
{
	if (bw->window != NULL) {
		guit->window->set_scroll(bw->window, x, y);
	} else {
		if (bw->scroll_x != NULL)
			scrollbar_set(bw->scroll_x, x, false);
		if (bw->scroll_y != NULL)
			scrollbar_set(bw->scroll_y, y, false);
	}
}

/**
 * Internal helper for getting the positional features
 *
 * \param[in] bw browser window to examine.
 * \param[in] x x-coordinate of point of interest
 * \param[in] y y-coordinate of point of interest
 * \param[out] data Feature structure to update.
 * \return NSERROR_OK or appropriate error code on faliure.
 */
static nserror
browser_window__get_contextual_content(struct browser_window *bw,
		int x, int y, struct browser_window_features *data)
{
	nserror ret = NSERROR_OK;

	/* Handle (i)frame scroll offset (core-managed browser windows only) */
	x += scrollbar_get_offset(bw->scroll_x);
	y += scrollbar_get_offset(bw->scroll_y);

	if (bw->children) {
		/* Browser window has children, so pass request on to
		 * appropriate child.
		 */
		struct browser_window *bwc;
		int cur_child;
		int children = bw->rows * bw->cols;

		/* Loop through all children of bw */
		for (cur_child = 0; cur_child < children; cur_child++) {
			/* Set current child */
			bwc = &bw->children[cur_child];

			/* Skip this frame if (x, y) coord lies outside */
			if ((x < bwc->x) ||
			    (bwc->x + bwc->width < x) ||
			    (y < bwc->y) ||
			    (bwc->y + bwc->height < y)) {
				continue;
			}

			/* Pass request into this child */
			return browser_window__get_contextual_content(bwc,
					(x - bwc->x), (y - bwc->y), data);
		}

		/* Coordinate not contained by any frame */

	} else if (bw->current_content != NULL) {
		/* Pass request to content */
		ret = content_get_contextual_content(bw->current_content,
						     x, y, data);
		data->main = bw->current_content;
	}

	return ret;
}

/* exported interface, documented in browser.h */
nserror browser_window_get_features(struct browser_window *bw,
		int x, int y, struct browser_window_features *data)
{
	/* clear the features structure to empty values */
	data->link = NULL;
	data->object = NULL;
	data->main = NULL;
	data->form_features = CTX_FORM_NONE;

	return browser_window__get_contextual_content(bw, x, y, data);
}

/* exported interface, documented in browser.h */
bool browser_window_scroll_at_point(struct browser_window *bw,
		int x, int y, int scrx, int scry)
{
	bool handled_scroll = false;
	assert(bw != NULL);

	/* Handle (i)frame scroll offset (core-managed browser windows only) */
	x += scrollbar_get_offset(bw->scroll_x);
	y += scrollbar_get_offset(bw->scroll_y);

	if (bw->children) {
		/* Browser window has children, so pass request on to
		 * appropriate child */
		struct browser_window *bwc;
		int cur_child;
		int children = bw->rows * bw->cols;

		/* Loop through all children of bw */
		for (cur_child = 0; cur_child < children; cur_child++) {
			/* Set current child */
			bwc = &bw->children[cur_child];

			/* Skip this frame if (x, y) coord lies outside */
			if (x < bwc->x || bwc->x + bwc->width < x ||
					y < bwc->y || bwc->y + bwc->height < y)
				continue;

			/* Pass request into this child */
			return browser_window_scroll_at_point(bwc,
					(x - bwc->x), (y - bwc->y),
					scrx, scry);
		}
	}

	/* Try to scroll any current content */
	if (bw->current_content != NULL && content_scroll_at_point(
			bw->current_content, x, y, scrx, scry) == true)
		/* Scroll handled by current content */
		return true;

	/* Try to scroll this window, if scroll not already handled */
	if (handled_scroll == false) {
		if (bw->scroll_y && scrollbar_scroll(bw->scroll_y, scry))
			handled_scroll = true;

		if (bw->scroll_x && scrollbar_scroll(bw->scroll_x, scrx))
			handled_scroll = true;
	}

	return handled_scroll;
}

/* exported interface, documented in browser.h */
bool browser_window_drop_file_at_point(struct browser_window *bw,
		int x, int y, char *file)
{
	assert(bw != NULL);

	/* Handle (i)frame scroll offset (core-managed browser windows only) */
	x += scrollbar_get_offset(bw->scroll_x);
	y += scrollbar_get_offset(bw->scroll_y);

	if (bw->children) {
		/* Browser window has children, so pass request on to
		 * appropriate child */
		struct browser_window *bwc;
		int cur_child;
		int children = bw->rows * bw->cols;

		/* Loop through all children of bw */
		for (cur_child = 0; cur_child < children; cur_child++) {
			/* Set current child */
			bwc = &bw->children[cur_child];

			/* Skip this frame if (x, y) coord lies outside */
			if (x < bwc->x || bwc->x + bwc->width < x ||
					y < bwc->y || bwc->y + bwc->height < y)
				continue;

			/* Pass request into this child */
			return browser_window_drop_file_at_point(bwc,
					(x - bwc->x), (y - bwc->y),
					file);
		}
	}

	/* Pass file drop on to any content */
	if (bw->current_content != NULL)
		return content_drop_file_at_point(bw->current_content,
				x, y, file);

	return false;
}

/* exported interface, documented in netsurf/browser_window.h */
void browser_window_set_gadget_filename(struct browser_window *bw,
		struct form_control *gadget, const char *fn)
{
	html_set_file_gadget_filename(bw->current_content, gadget, fn);
}

/* exported interface, documented in browser.h */
nserror browser_window_debug_dump(struct browser_window *bw,
				  FILE *f, enum content_debug op)
{
	if (bw->current_content != NULL) {
		return content_debug_dump(bw->current_content, f, op);
	}
	return NSERROR_OK;
}

/* exported interface, documented in browser.h */
nserror browser_window_debug(struct browser_window *bw, enum content_debug op)
{
	if (bw->current_content != NULL) {
		return content_debug(bw->current_content, op);
	}
	return NSERROR_OK;
}

/** slow script handler
*/
static bool slow_script(void *ctx)
{
	static int count = 0;
	LOG("Continuing execution %d", count);
	count++;
	if (count > 1) {
		count = 0;
		return false;
	}
	return true;
}

/* exported interface, documented in netsurf/browser_window.h */
nserror browser_window_create(enum browser_window_create_flags flags,
		nsurl *url, nsurl *referrer,
		struct browser_window *existing,
		struct browser_window **bw)
{
	gui_window_create_flags gw_flags = GW_CREATE_NONE;
	struct browser_window *ret;
	nserror err;

	/* Check parameters */
	if (flags & BW_CREATE_CLONE) {
		if (existing == NULL) {
			assert(0 && "Failed: No existing window provided.");
			return NSERROR_BAD_PARAMETER;
		}
	}
	if (!(flags & BW_CREATE_HISTORY)) {
		if (!(flags & BW_CREATE_CLONE) || existing == NULL) {
			assert(0 && "Failed: Must have existing for history.");
			return NSERROR_BAD_PARAMETER;
		}
	}


	if ((ret = calloc(1, sizeof(struct browser_window))) == NULL) {
		return NSERROR_NOMEM;
	}

	/* Initialise common parts */
	err = browser_window_initialise_common(flags, ret, existing);
	if (err != NSERROR_OK) {
		browser_window_destroy(ret);
		return err;
	}

	/* window characteristics */
	ret->browser_window_type = BROWSER_WINDOW_NORMAL;
	ret->scrolling = BW_SCROLLING_YES;
	ret->border = true;
	ret->no_resize = true;
	ret->focus = ret;

	/* initialise last action with creation time */
	nsu_getmonotonic_ms(&ret->last_action);

	/* The existing gui_window is on the top-level existing
	 * browser_window. */
	existing = browser_window_get_root(existing);

	/* Set up gui_window creation flags */
	if (flags & BW_CREATE_TAB)
		gw_flags |= GW_CREATE_TAB;
	if (flags & BW_CREATE_CLONE)
		gw_flags |= GW_CREATE_CLONE;

	ret->window = guit->window->create(ret,
			(existing != NULL) ? existing->window : NULL,
			gw_flags);

	if (ret->window == NULL) {
		browser_window_destroy(ret);
		return NSERROR_BAD_PARAMETER;
	}

	if (url != NULL) {
		enum browser_window_nav_flags nav_flags = BW_NAVIGATE_NONE;
		if (flags & BW_CREATE_UNVERIFIABLE)
			nav_flags |= BW_NAVIGATE_UNVERIFIABLE;
		if (flags & BW_CREATE_HISTORY)
			nav_flags |= BW_NAVIGATE_HISTORY;
		browser_window_navigate(ret, url, referrer, nav_flags, NULL,
				NULL, NULL);
	}

	if (bw != NULL) {
		*bw = ret;
	}

	return NSERROR_OK;
}


/* exported internal interface, documented in desktop/browser_private.h */
nserror browser_window_initialise_common(enum browser_window_create_flags flags,
		struct browser_window *bw, struct browser_window *existing)
{
	nserror err;
	assert(bw);

	/* new javascript context for each window/(i)frame */
	err = js_newcontext(nsoption_int(script_timeout),
				  slow_script, NULL, &bw->jsctx);
	if (err != NSERROR_OK)
		return err;

	if (flags & BW_CREATE_CLONE) {
		assert(existing != NULL);

		/* clone history */
		err = browser_window_history_clone(existing, bw);

		/* copy the scale */
		bw->scale = existing->scale;
	} else {
		/* create history */
		err = browser_window_history_create(bw);

		/* default scale */
		bw->scale = (float) nsoption_int(scale) / 100.0;
	}

	if (err != NSERROR_OK)
		return err;

	/* window characteristics */
	bw->refresh_interval = -1;

	bw->drag_type = DRAGGING_NONE;

	bw->scroll_x = NULL;
	bw->scroll_y = NULL;

	bw->focus = NULL;

	/* initialise status text cache */
	bw->status_text = NULL;
	bw->status_text_len = 0;
	bw->status_match = 0;
	bw->status_miss = 0;

	return NSERROR_OK;
}

/**
 * implements the download operation of a window navigate
 */
static nserror
browser_window_download(struct browser_window *bw,
			nsurl *url,
			nsurl *nsref,
			uint32_t fetch_flags,
			bool fetch_is_post,
			llcache_post_data *post)
{
	llcache_handle *l;
	struct browser_window *root;
	nserror error;

	root = browser_window_get_root(bw);
	assert(root != NULL);

	fetch_flags |= LLCACHE_RETRIEVE_FORCE_FETCH;
	fetch_flags |= LLCACHE_RETRIEVE_STREAM_DATA;

	error = llcache_handle_retrieve(url, fetch_flags, nsref,
					fetch_is_post ? post : NULL,
					NULL, NULL, &l);
	if (error == NSERROR_NO_FETCH_HANDLER) {
		/* no internal handler for this type, call out to frontend */
		error = guit->misc->launch_url(url);
	} else if (error != NSERROR_OK) {
		LOG("Failed to fetch download: %d", error);
	} else {
		error = download_context_create(l, root->window);
		if (error != NSERROR_OK) {
			LOG("Failed creating download context: %d", error);
			llcache_handle_abort(l);
			llcache_handle_release(l);
		}
	}

	return error;
}


static bool browser_window_check_throbber(struct browser_window *bw)
{
	int children, index;

	if (bw->throbbing)
		return true;

	if (bw->children) {
		children = bw->rows * bw->cols;
		for (index = 0; index < children; index++) {
			if (browser_window_check_throbber(&bw->children[index]))
				return true;
		}
	}
	if (bw->iframes) {
		for (index = 0; index < bw->iframe_count; index++) {
			if (browser_window_check_throbber(&bw->iframes[index]))
				return true;
		}
	}
	return false;
}


/**
 * Start the busy indicator.
 *
 * \param bw browser window
 */

static void browser_window_start_throbber(struct browser_window *bw)
{
	bw->throbbing = true;

	while (bw->parent)
		bw = bw->parent;

	guit->window->start_throbber(bw->window);
}


/**
 * Stop the busy indicator.
 *
 * \param  bw  browser window
 */
static void browser_window_stop_throbber(struct browser_window *bw)
{
	bw->throbbing = false;

	while (bw->parent)
		bw = bw->parent;

	if (!browser_window_check_throbber(bw)) {
		guit->window->stop_throbber(bw->window);
	}
}



/**
 * Callback for fetchcache() for browser window favicon fetches.
 */
static nserror browser_window_favicon_callback(hlcache_handle *c,
		const hlcache_event *event, void *pw)
{
	struct browser_window *bw = pw;

	switch (event->type) {
	case CONTENT_MSG_DONE:
		if (bw->current_favicon != NULL) {
			content_status status =
					content_get_status(bw->current_favicon);

			if ((status == CONTENT_STATUS_READY) ||
					(status == CONTENT_STATUS_DONE))
				content_close(bw->current_favicon);

			hlcache_handle_release(bw->current_favicon);
		}

		bw->current_favicon = c;
		bw->loading_favicon = NULL;

		/* content_get_bitmap on the hlcache_handle should give
		 *   us the favicon bitmap at this point
		 */
		guit->window->set_icon(bw->window, c);
		break;

	case CONTENT_MSG_ERROR:

		/* clean up after ourselves */
		if (c == bw->loading_favicon)
			bw->loading_favicon = NULL;
		else if (c == bw->current_favicon) {
			bw->current_favicon = NULL;
		}

		hlcache_handle_release(c);

		if (bw->failed_favicon == false) {
			nsurl *nsref = NULL;
			nsurl *nsurl;
			nserror error;

			bw->failed_favicon = true;

			error = nsurl_create("resource:favicon.ico", &nsurl);
			if (error != NSERROR_OK) {
				LOG("Unable to create default location url");
			} else {

				hlcache_handle_retrieve(nsurl,
						HLCACHE_RETRIEVE_SNIFF_TYPE,
						nsref, NULL,
						browser_window_favicon_callback,
						bw, NULL, CONTENT_IMAGE,
						&bw->loading_favicon);

				nsurl_unref(nsurl);
			}

		}
		break;

	default:
		break;
	}
	return NSERROR_OK;
}

static void browser_window_update_favicon(hlcache_handle *c,
		struct browser_window *bw, struct content_rfc5988_link *link)
{
	nsurl *nsref = NULL;
	nsurl *nsurl;
	nserror error;

	assert(c != NULL);
	assert(bw !=NULL);

	if (bw->window == NULL)
		/* Not top-level browser window; not interested */
		return;

	/* already fetching the favicon - use that */
	if (bw->loading_favicon != NULL)
		return;

	bw->failed_favicon = false;

	if (link == NULL) {
		/* Look for "icon" */
		link = content_find_rfc5988_link(c, corestring_lwc_icon);
	}

	if (link == NULL) {
		/* Look for "shortcut icon" */
		link = content_find_rfc5988_link(c,
				corestring_lwc_shortcut_icon);
	}

	if (link == NULL) {
		lwc_string *scheme;
		bool speculative_default = false;
		bool match;

		nsurl = hlcache_handle_get_url(c);

		scheme = nsurl_get_component(nsurl, NSURL_SCHEME);

		/* If the document was fetched over http(s), then speculate
		 * that there's a favicon living at /favicon.ico */
		if ((lwc_string_caseless_isequal(scheme, corestring_lwc_http,
				&match) == lwc_error_ok && match) ||
		    (lwc_string_caseless_isequal(scheme, corestring_lwc_https,
				&match) == lwc_error_ok && match)) {
			speculative_default = true;
		}

		lwc_string_unref(scheme);

		if (speculative_default) {
			/* no favicon via link, try for the default location */
			error = nsurl_join(nsurl, "/favicon.ico", &nsurl);
		} else {
			bw->failed_favicon = true;
			error = nsurl_create("resource:favicon.ico", &nsurl);
		}
		if (error != NSERROR_OK) {
			LOG("Unable to create default location url");
			return;
		}
	} else {
		nsurl = nsurl_ref(link->href);
	}

	if (link == NULL) {
		LOG("fetching general favicon from '%s'", nsurl_access(nsurl));
	} else {
		LOG("fetching favicon rel:%s '%s'", lwc_string_data(link->rel), nsurl_access(nsurl));
	}

	hlcache_handle_retrieve(nsurl, HLCACHE_RETRIEVE_SNIFF_TYPE,
			nsref, NULL, browser_window_favicon_callback,
			bw, NULL, CONTENT_IMAGE, &bw->loading_favicon);

	nsurl_unref(nsurl);
}

/**
 * window callback errorcode handling.
 */
static void
browser_window_callback_errorcode(hlcache_handle *c,
				  struct browser_window *bw,
				  nserror code)
{
	const char* message;

	message = messages_get_errorcode(code);

	browser_window_set_status(bw, message);

	/* Only warn the user about errors in top-level windows */
	if (bw->browser_window_type == BROWSER_WINDOW_NORMAL) {
		guit->misc->warning(message, NULL);
	}

	if (c == bw->loading_content) {
		bw->loading_content = NULL;
	} else if (c == bw->current_content) {
		bw->current_content = NULL;
		browser_window_remove_caret(bw, false);
	}

	hlcache_handle_release(c);

	browser_window_stop_throbber(bw);
}


/**
 * Handle meta http-equiv refresh time elapsing by loading a new page.
 *
 * \param p browser window to refresh with new page
 */
static void browser_window_refresh(void *p)
{
	struct browser_window *bw = p;
	nsurl *url;
	nsurl *refresh;
	hlcache_handle *parent = NULL;
	enum browser_window_nav_flags flags = BW_NAVIGATE_UNVERIFIABLE;

	assert(bw->current_content != NULL &&
		(content_get_status(bw->current_content) ==
				CONTENT_STATUS_READY ||
		content_get_status(bw->current_content) ==
				CONTENT_STATUS_DONE));

	/* Ignore if the refresh URL has gone
	 * (may happen if a fetch error occurred) */
	refresh = content_get_refresh_url(bw->current_content);
	if (refresh == NULL)
		return;

	/* mark this content as invalid so it gets flushed from the cache */
	content_invalidate_reuse_data(bw->current_content);

	url = hlcache_handle_get_url(bw->current_content);
	if ((url == NULL) || (nsurl_compare(url, refresh, NSURL_COMPLETE))) {
		flags |= BW_NAVIGATE_HISTORY;
	}

	/* Treat an (almost) immediate refresh in a top-level browser window as
	 * if it were an HTTP redirect, and thus make the resulting fetch
	 * verifiable.
	 *
	 * See fetchcache.c for why redirected fetches should be verifiable at
	 * all.
	 */
	if (bw->refresh_interval <= 100 && bw->parent == NULL) {
		flags &= ~BW_NAVIGATE_UNVERIFIABLE;
	} else {
		parent = bw->current_content;
	}

	browser_window_navigate(bw,
				refresh,
				url,
				flags,
				NULL,
				NULL,
				parent);

}


/**
 * Transfer the loading_content to a new download window.
 */

static void browser_window_convert_to_download(struct browser_window *bw,
		llcache_handle *stream)
{
	struct browser_window *root = browser_window_get_root(bw);
	nserror error;

	assert(root != NULL);

	error = download_context_create(stream, root->window);
	if (error != NSERROR_OK) {
		llcache_handle_abort(stream);
		llcache_handle_release(stream);
	}

	/* remove content from browser window */
	hlcache_handle_release(bw->loading_content);
	bw->loading_content = NULL;

	browser_window_stop_throbber(bw);
}


/**
 * Browser window content event callback handler.
 */
static nserror browser_window_callback(hlcache_handle *c,
		const hlcache_event *event, void *pw)
{
	struct browser_window *bw = pw;
	nserror res = NSERROR_OK;

	switch (event->type) {
	case CONTENT_MSG_DOWNLOAD:
		assert(bw->loading_content == c);

		browser_window_convert_to_download(bw, event->data.download);

		if (bw->current_content != NULL) {
			browser_window_refresh_url_bar(bw);
		}
		break;

	case CONTENT_MSG_LOADING:
		assert(bw->loading_content == c);

#ifdef WITH_THEME_INSTALL
		if (content_get_type(c) == CONTENT_THEME) {
			theme_install_start(c);
			bw->loading_content = NULL;
			browser_window_stop_throbber(bw);
		} else
#endif
		{
			bw->refresh_interval = -1;
			browser_window_set_status(bw,
					content_get_status_message(c));
		}
		break;

	case CONTENT_MSG_READY:
	{
		int width, height;

		assert(bw->loading_content == c);

		if (bw->current_content != NULL) {
			content_status status =
					content_get_status(bw->current_content);

			if (status == CONTENT_STATUS_READY ||
					status == CONTENT_STATUS_DONE)
				content_close(bw->current_content);

			hlcache_handle_release(bw->current_content);
		}

		bw->current_content = c;
		bw->loading_content = NULL;

		/* Format the new content to the correct dimensions */
		browser_window_get_dimensions(bw, &width, &height, true);
		content_reformat(c, false, width, height);

		browser_window_remove_caret(bw, false);

		if (bw->window != NULL) {
			guit->window->new_content(bw->window);

			browser_window_refresh_url_bar(bw);
		}

		/* new content; set scroll_to_top */
		browser_window_update(bw, true);
		content_open(c, bw, 0, 0);
		browser_window_set_status(bw, content_get_status_message(c));

		/* history */
		if (bw->history_add && bw->history) {
			nsurl *url = hlcache_handle_get_url(c);

			if (urldb_add_url(url)) {
				urldb_set_url_title(url, content_get_title(c));
				urldb_update_url_visit_data(url);
				urldb_set_url_content_type(url,
						content_get_type(c));

				/* This is safe as we've just added the URL */
				global_history_add(urldb_get_url(url));
			}
			/** \todo Urldb / Thumbnails / Local history brokenness
			 *
			 * We add to local history after calling urldb_add_url
			 * rather than in the block above.  If urldb_add_url
			 * fails (as it will for urls like "about:about",
			 * "about:config" etc), there would be no local history
			 * node, and later calls to history_update will either
			 * explode or overwrite the node for the previous URL.
			 *
			 * We call it after, rather than before urldb_add_url
			 * because history_add calls bitmap render, which
			 * tries to register the thumbnail with urldb.  That
			 * thumbnail registration fails if the url doesn't
			 * exist in urldb already, and only urldb-registered
			 * thumbnails get freed.  So if we called history_add
			 * before urldb_add_url we would leak thumbnails for
			 * all newly visited URLs.  With the history_add call
			 * after, we only leak the thumbnails when urldb does
			 * not add the URL.
			 */
			browser_window_history_add(bw, c, bw->frag_id);
		}

		/* frames */
		if ((content_get_type(c) == CONTENT_HTML) &&
		    (html_get_frameset(c) != NULL)) {
			res = browser_window_create_frameset(bw,
					html_get_frameset(c));
		}
		if (content_get_type(c) == CONTENT_HTML &&
				html_get_iframe(c) != NULL)
			browser_window_create_iframes(bw, html_get_iframe(c));
	}
		break;

	case CONTENT_MSG_DONE:
		assert(bw->current_content == c);

		if (bw->window == NULL) {
			/* Updated browser window's scrollbars.
			 * TODO: do this before CONTENT_MSG_DONE */
			browser_window_reformat(bw, true,
					bw->width, bw->height);
			browser_window_handle_scrollbars(bw);
		}

		browser_window_update(bw, false);
		browser_window_set_status(bw, content_get_status_message(c));
		browser_window_stop_throbber(bw);
		browser_window_update_favicon(c, bw, NULL);

		browser_window_history_update(bw, c);
		hotlist_update_url(hlcache_handle_get_url(c));

		if (bw->refresh_interval != -1) {
			guit->misc->schedule(bw->refresh_interval * 10,
					browser_window_refresh, bw);
		}
		break;

	case CONTENT_MSG_ERRORCODE:
		browser_window_callback_errorcode(c, bw, event->data.errorcode);
		break;

	case CONTENT_MSG_ERROR:
		browser_window_set_status(bw, event->data.error);

		/* Only warn the user about errors in top-level windows */
		if (bw->browser_window_type == BROWSER_WINDOW_NORMAL) {
			guit->misc->warning(event->data.error, NULL);
		}

		if (c == bw->loading_content)
			bw->loading_content = NULL;
		else if (c == bw->current_content) {
			bw->current_content = NULL;
			browser_window_remove_caret(bw, false);
		}

		hlcache_handle_release(c);

		browser_window_stop_throbber(bw);
		break;

	case CONTENT_MSG_REDIRECT:
		if (urldb_add_url(event->data.redirect.from))
			urldb_update_url_visit_data(event->data.redirect.from);
		break;

	case CONTENT_MSG_STATUS:
		if (event->data.explicit_status_text == NULL) {
			/* Object content's status text updated */
			const char *status = NULL;
			if (bw->loading_content != NULL)
				/* Give preference to any loading content */
				status = content_get_status_message(
						bw->loading_content);

			if (status == NULL)
				status = content_get_status_message(c);

			if (status != NULL)
				browser_window_set_status(bw, status);
		} else {
			/* Object content wants to set explicit message */
			browser_window_set_status(bw,
					event->data.explicit_status_text);
		}
		break;

	case CONTENT_MSG_REFORMAT:
		if (c == bw->current_content &&
			content_get_type(c) == CONTENT_HTML) {
			/* reposition frames */
			if (html_get_frameset(c) != NULL)
				browser_window_recalculate_frameset(bw);
			/* reflow iframe positions */
			if (html_get_iframe(c) != NULL)
				browser_window_recalculate_iframes(bw);
		}

		/* Hide any caret, but don't remove it */
		browser_window_remove_caret(bw, true);

		if (!(event->data.background)) {
			/* Reformatted content should be redrawn */
			browser_window_update(bw, false);
		}
		break;

	case CONTENT_MSG_REDRAW:
	{
		struct rect rect = {
			.x0 = event->data.redraw.x,
			.y0 = event->data.redraw.y,
			.x1 = event->data.redraw.x + event->data.redraw.width,
			.y1 = event->data.redraw.y + event->data.redraw.height
		};

		browser_window_update_box(bw, &rect);
	}
		break;

	case CONTENT_MSG_REFRESH:
		bw->refresh_interval = event->data.delay * 100;
		break;

	case CONTENT_MSG_LINK: /* content has an rfc5988 link element */
	{
		bool match;

		/* Handle "icon" and "shortcut icon" */
		if ((lwc_string_caseless_isequal(
				event->data.rfc5988_link->rel,
				corestring_lwc_icon,
				&match) == lwc_error_ok && match) ||
		    (lwc_string_caseless_isequal(
				event->data.rfc5988_link->rel,
				corestring_lwc_shortcut_icon,
				&match) == lwc_error_ok && match)) {
			/* it's a favicon perhaps start a fetch for it */
			browser_window_update_favicon(c, bw,
					event->data.rfc5988_link);
		}
	}
		break;

	case CONTENT_MSG_GETCTX:
		/* only the content object created by the browser
		 * window requires a new global compartment object
		 */
		assert(bw->loading_content == c);
		if (js_newcompartment(bw->jsctx,
				      bw,
				      hlcache_handle_get_content(c)) != NULL) {
			*(event->data.jscontext) = bw->jsctx;
		}
		break;

	case CONTENT_MSG_SCROLL:
		/* Content wants to be scrolled */
		if (bw->current_content != c)
			break;

		if (event->data.scroll.area) {
			struct rect rect = {
				.x0 = event->data.scroll.x0,
				.y0 = event->data.scroll.y0,
				.x1 = event->data.scroll.x1,
				.y1 = event->data.scroll.y1
			};
			browser_window_scroll_visible(bw, &rect);
		} else {
			browser_window_set_scroll(bw,
					event->data.scroll.x0,
					event->data.scroll.y0);
		}

		break;

	case CONTENT_MSG_DRAGSAVE:
	{
		/* Content wants drag save of a content */
		struct browser_window *root = browser_window_get_root(bw);
		hlcache_handle *save = event->data.dragsave.content;

		if (save == NULL) {
			save = c;
		}

		switch(event->data.dragsave.type) {
		case CONTENT_SAVE_ORIG:
			guit->window->drag_save_object(root->window, save,
						       GUI_SAVE_OBJECT_ORIG);
			break;

		case CONTENT_SAVE_NATIVE:
			guit->window->drag_save_object(root->window, save,
						       GUI_SAVE_OBJECT_NATIVE);
			break;

		case CONTENT_SAVE_COMPLETE:
			guit->window->drag_save_object(root->window, save,
						       GUI_SAVE_COMPLETE);
			break;

		case CONTENT_SAVE_SOURCE:
			guit->window->drag_save_object(root->window, save,
						       GUI_SAVE_SOURCE);
			break;
		}
	}
		break;

	case CONTENT_MSG_SAVELINK:
	{
		/* Content wants a link to be saved */
		struct browser_window *root = browser_window_get_root(bw);
		guit->window->save_link(root->window,
				event->data.savelink.url,
				event->data.savelink.title);
	}
		break;

	case CONTENT_MSG_POINTER:
		/* Content wants to have specific mouse pointer */
		browser_window_set_pointer(bw, event->data.pointer);
		break;

	case CONTENT_MSG_DRAG:
	{
		browser_drag_type bdt = DRAGGING_NONE;

		switch (event->data.drag.type) {
		case CONTENT_DRAG_NONE:
			bdt = DRAGGING_NONE;
			break;
		case CONTENT_DRAG_SCROLL:
			bdt = DRAGGING_CONTENT_SCROLLBAR;
			break;
		case CONTENT_DRAG_SELECTION:
			bdt = DRAGGING_SELECTION;
			break;
		}
		browser_window_set_drag_type(bw, bdt, event->data.drag.rect);
	}
		break;

	case CONTENT_MSG_CARET:
		switch (event->data.caret.type) {
		case CONTENT_CARET_REMOVE:
			browser_window_remove_caret(bw, false);
			break;
		case CONTENT_CARET_HIDE:
			browser_window_remove_caret(bw, true);
			break;
		case CONTENT_CARET_SET_POS:
			browser_window_place_caret(bw,
					event->data.caret.pos.x,
					event->data.caret.pos.y,
					event->data.caret.pos.height,
					event->data.caret.pos.clip);
			break;
		}
		break;

	case CONTENT_MSG_SELECTION:
		browser_window_set_selection(bw,
				event->data.selection.selection,
				event->data.selection.read_only);
		break;

	case CONTENT_MSG_SELECTMENU:
		if (event->data.select_menu.gadget->type == GADGET_SELECT) {
			struct browser_window *root =
					browser_window_get_root(bw);
			guit->window->create_form_select_menu(root->window,
					event->data.select_menu.gadget);
		}

		break;

	case CONTENT_MSG_GADGETCLICK:
		if (event->data.gadget_click.gadget->type == GADGET_FILE) {
			struct browser_window *root =
					browser_window_get_root(bw);
			guit->window->file_gadget_open(root->window, c,
				event->data.gadget_click.gadget);
		}

		break;

	default:
		break;
	}

	return res;
}


/* Have to forward declare browser_window_destroy_internal */
static void browser_window_destroy_internal(struct browser_window *bw);

/**
 * Close and destroy all child browser window.
 *
 * \param  bw  browser window
 */
static void browser_window_destroy_children(struct browser_window *bw)
{
	int i;

	if (bw->children) {
		for (i = 0; i < (bw->rows * bw->cols); i++)
			browser_window_destroy_internal(&bw->children[i]);
		free(bw->children);
		bw->children = NULL;
		bw->rows = 0;
		bw->cols = 0;
	}
	if (bw->iframes) {
		for (i = 0; i < bw->iframe_count; i++)
			browser_window_destroy_internal(&bw->iframes[i]);
		free(bw->iframes);
		bw->iframes = NULL;
		bw->iframe_count = 0;
	}
}


/**
 * Release all memory associated with a browser window.
 *
 * \param  bw  browser window
 */
static void browser_window_destroy_internal(struct browser_window *bw)
{
	assert(bw);

	LOG("Destroying window");

	if (bw->children != NULL || bw->iframes != NULL) {
		browser_window_destroy_children(bw);
	}

	/* Destroy scrollbars */
	if (bw->scroll_x != NULL) {
		scrollbar_destroy(bw->scroll_x);
	}

	if (bw->scroll_y != NULL) {
		scrollbar_destroy(bw->scroll_y);
	}

	/* clear any pending callbacks */
	guit->misc->schedule(-1, browser_window_refresh, bw);
	/* The ugly cast here is so the reformat function can be
	 * passed a gui window pointer in its API rather than void*
	 */
	LOG("Clearing schedule %p(%p)", guit->window->reformat, bw->window);
	guit->misc->schedule(-1, (void(*)(void*))guit->window->reformat, bw->window);

	/* If this brower window is not the root window, and has focus, unset
	 * the root browser window's focus pointer. */
	if (!bw->window) {
		struct browser_window *top = browser_window_get_root(bw);

		if (top->focus == bw)
			top->focus = top;

		if (top->selection.bw == bw) {
			browser_window_set_selection(top, false, false);
		}
	}

	/* Destruction order is important: we must ensure that the frontend
	 * destroys any window(s) associated with this browser window before
	 * we attempt any destructive cleanup.
	 */

	if (bw->window) {
		/* Only the root window has a GUI window */
		guit->window->destroy(bw->window);
	}

	if (bw->loading_content != NULL) {
		hlcache_handle_abort(bw->loading_content);
		hlcache_handle_release(bw->loading_content);
		bw->loading_content = NULL;
	}

	if (bw->current_content != NULL) {
		content_status status = content_get_status(bw->current_content);
		if (status == CONTENT_STATUS_READY ||
				status == CONTENT_STATUS_DONE)
			content_close(bw->current_content);

		hlcache_handle_release(bw->current_content);
		bw->current_content = NULL;
	}

	if (bw->loading_favicon != NULL) {
		hlcache_handle_abort(bw->loading_favicon);
		hlcache_handle_release(bw->loading_favicon);
		bw->loading_favicon = NULL;
	}

	if (bw->current_favicon != NULL) {
		content_status status = content_get_status(bw->current_favicon);

		if (status == CONTENT_STATUS_READY ||
		    status == CONTENT_STATUS_DONE)
			content_close(bw->current_favicon);

		hlcache_handle_release(bw->current_favicon);
		bw->current_favicon = NULL;
	}

	if (bw->box != NULL) {
		bw->box->iframe = NULL;
		bw->box = NULL;
	}

	if (bw->jsctx != NULL) {
		js_destroycontext(bw->jsctx);
	}

	/* These simply free memory, so are safe here */

	if (bw->frag_id != NULL)
		lwc_string_unref(bw->frag_id);

	browser_window_history_destroy(bw);

	free(bw->name);
	free(bw->status_text);
	bw->status_text = NULL;
	LOG("Status text cache match:miss %d:%d", bw->status_match, bw->status_miss);
}

/**
 * Update URL bar for a given browser window to given URL
 *
 * \param bw	Browser window to update URL bar for.
 * \param url	URL for content displayed by bw including any fragment.
 */
static inline nserror 
browser_window_refresh_url_bar_internal(struct browser_window *bw, nsurl *url)
{
	assert(bw);
	assert(url);

	if ((bw->parent != NULL) || (bw->window == NULL)) {
		/* Not root window or no gui window so do not set a URL */
		return NSERROR_OK;
	}

	return guit->window->set_url(bw->window, url);
}


/* exported interface, documented in netsurf/browser_window.h */
void browser_window_destroy(struct browser_window *bw)
{
	/* can't destoy child windows on their own */
	assert(!bw->parent);

	/* destroy */
	browser_window_destroy_internal(bw);
	free(bw);
}

/* exported interface, documented in netsurf/browser_window.h */
nserror browser_window_refresh_url_bar(struct browser_window *bw)
{
	nserror ret;
	nsurl *display_url;

	assert(bw);

	if (bw->parent != NULL) {
		/* Not root window; don't set a URL in GUI URL bar */
		return NSERROR_OK;
	}

	if (bw->current_content == NULL) {
		/* no content so return about:blank */
		ret = browser_window_refresh_url_bar_internal(bw,
				corestring_nsurl_about_blank);
	} else if (bw->frag_id == NULL) {
		ret = browser_window_refresh_url_bar_internal(bw,
				hlcache_handle_get_url(bw->current_content));
	} else {
		/* Combine URL and Fragment */
		ret = nsurl_refragment(
				hlcache_handle_get_url(bw->current_content),
				bw->frag_id, &display_url);
		if (ret == NSERROR_OK) {
			ret = browser_window_refresh_url_bar_internal(bw,
					display_url);
			nsurl_unref(display_url);
		}
	}

	return ret;
}


/* exported interface documented in netsurf/browser_window.h */
nserror browser_window_navigate(struct browser_window *bw,
			     nsurl *url,
			     nsurl *referrer,
			     enum browser_window_nav_flags flags,
			     char *post_urlenc,
			     struct fetch_multipart_data *post_multipart,
			     hlcache_handle *parent)
{
	hlcache_handle *c;
	int depth = 0;
	struct browser_window *cur;
	uint32_t fetch_flags = 0;
	bool fetch_is_post = (post_urlenc != NULL || post_multipart != NULL);
	llcache_post_data post;
	hlcache_child_context child;
	nserror error;

	assert(bw);
	assert(url);

	LOG("bw %p, url %s", bw, nsurl_access(url));

	/* don't allow massively nested framesets */
	for (cur = bw; cur->parent; cur = cur->parent) {
		depth++;
	}
	if (depth > FRAME_DEPTH) {
		LOG("frame depth too high.");
		return NSERROR_FRAME_DEPTH;
	}

	/* Set up retrieval parameters */
	if (!(flags & BW_NAVIGATE_UNVERIFIABLE)) {
		fetch_flags |= LLCACHE_RETRIEVE_VERIFIABLE;
	}

	if (post_multipart != NULL) {
		post.type = LLCACHE_POST_MULTIPART;
		post.data.multipart = post_multipart;
	} else if (post_urlenc != NULL) {
		post.type = LLCACHE_POST_URL_ENCODED;
		post.data.urlenc = post_urlenc;
	}

	child.charset = content_get_encoding(parent, CONTENT_ENCODING_NORMAL);
	if ((parent != NULL) && (content_get_type(parent) == CONTENT_HTML)) {
		child.quirks = content_get_quirks(parent);
	}

	url = nsurl_ref(url);

	if (referrer != NULL) {
		referrer = nsurl_ref(referrer);
	}

	/* Get download out of the way */
	if ((flags & BW_NAVIGATE_DOWNLOAD) != 0) {
		error = browser_window_download(bw,
						url,
						referrer,
						fetch_flags,
						fetch_is_post,
						&post);
		nsurl_unref(url);
		if (referrer != NULL) {
			nsurl_unref(referrer);
		}
		return error;
	}

	if (bw->frag_id != NULL) {
		lwc_string_unref(bw->frag_id);
	}
	bw->frag_id = NULL;

	if (nsurl_has_component(url, NSURL_FRAGMENT)) {
		bool same_url = false;

		bw->frag_id = nsurl_get_component(url, NSURL_FRAGMENT);

		/* Compare new URL with existing one (ignoring fragments) */
		if ((bw->current_content != NULL) &&
		    (hlcache_handle_get_url(bw->current_content) != NULL)) {
			same_url = nsurl_compare(url,
					hlcache_handle_get_url(
							bw->current_content),
					NSURL_COMPLETE);
		}

		/* if we're simply moving to another ID on the same page,
		 * don't bother to fetch, just update the window.
		 */
		if ((same_url) &&
		    (fetch_is_post == false) &&
		    (nsurl_has_component(url, NSURL_QUERY) == false)) {
			nsurl_unref(url);

			if (referrer != NULL) {
				nsurl_unref(referrer);
			}

			if ((flags & BW_NAVIGATE_HISTORY) != 0) {
				browser_window_history_add(bw,
					    bw->current_content, bw->frag_id);
			}

			browser_window_update(bw, false);

			if (bw->current_content != NULL) {
				browser_window_refresh_url_bar(bw);
			}
			return NSERROR_OK;
		}
	}

	browser_window_stop(bw);
	browser_window_remove_caret(bw, false);
	browser_window_destroy_children(bw);

	LOG("Loading '%s'", nsurl_access(url));

	browser_window_set_status(bw, messages_get("Loading"));
	bw->history_add = (flags & BW_NAVIGATE_HISTORY);

	/* Verifiable fetches may trigger a download */
	if (!(flags & BW_NAVIGATE_UNVERIFIABLE)) {
		fetch_flags |= HLCACHE_RETRIEVE_MAY_DOWNLOAD;
	}

	error = hlcache_handle_retrieve(url,
			fetch_flags | HLCACHE_RETRIEVE_SNIFF_TYPE,
			referrer,
			fetch_is_post ? &post : NULL,
			browser_window_callback, bw,
			parent != NULL ? &child : NULL,
			CONTENT_ANY, &c);

	switch (error) {
	case NSERROR_OK:
		bw->loading_content = c;
		browser_window_start_throbber(bw);
		error = browser_window_refresh_url_bar_internal(bw, url);
		break;

	case NSERROR_NO_FETCH_HANDLER: /* no handler for this type */
		/** \todo does this always try and download even
		 * unverifiable content?
		 */
		error = guit->misc->launch_url(url);
		break;

	default: /* report error to user */
		browser_window_set_status(bw, messages_get_errorcode(error));
		/** @todo should the caller report the error? */
		guit->misc->warning(messages_get_errorcode(error), NULL);
		break;

	}

	nsurl_unref(url);
	if (referrer != NULL) {
		nsurl_unref(referrer);
	}

	/* Record time */
	nsu_getmonotonic_ms(&bw->last_action);

	return error;
}


/* Exported interface, documented in browser.h */
bool browser_window_up_available(struct browser_window *bw)
{
	bool result = false;

	if (bw != NULL && bw->current_content != NULL) {
		nsurl *parent;
		nserror	err = nsurl_parent(hlcache_handle_get_url(
				bw->current_content), &parent);
		if (err == NSERROR_OK) {
			result = nsurl_compare(hlcache_handle_get_url(
					bw->current_content), parent,
					NSURL_COMPLETE) == false;
			nsurl_unref(parent);
		}
	}

	return result;
}


/* Exported interface, documented in browser.h */
nserror browser_window_navigate_up(struct browser_window *bw, bool new_window)
{
	nsurl *current, *parent;
	nserror err;

	if (bw == NULL)
		return NSERROR_BAD_PARAMETER;

	current = browser_window_get_url(bw);

	err = nsurl_parent(current, &parent);
	if (err != NSERROR_OK) {
		return err;
	}

	if (nsurl_compare(current, parent, NSURL_COMPLETE) == true) {
		/* Can't go up to parent from here */
		nsurl_unref(parent);
		return NSERROR_OK;
	}

	if (new_window) {
		err = browser_window_create(BW_CREATE_CLONE,
				parent, NULL, bw, NULL);
	} else {
		err = browser_window_navigate(bw, parent, NULL,
				BW_NAVIGATE_HISTORY, NULL, NULL, NULL);
	}

	nsurl_unref(parent);
	return err;
}


/* Exported interface, documented in browser.h */
nsurl* browser_window_get_url(struct browser_window *bw)
{
	assert(bw != NULL);

	if (bw->current_content != NULL) {
		return hlcache_handle_get_url(bw->current_content);

	} else if (bw->loading_content != NULL) {
		/* TODO: should we return this? */
		return hlcache_handle_get_url(bw->loading_content);
	}

	return corestring_nsurl_about_blank;
}

/* Exported interface, documented in browser.h */
const char* browser_window_get_title(struct browser_window *bw)
{
	assert(bw != NULL);

	if (bw->current_content != NULL) {
		return content_get_title(bw->current_content);
	}

	/* no content so return about:blank */
	return nsurl_access(corestring_nsurl_about_blank);	
}

/* Exported interface, documented in browser.h */
struct history * browser_window_get_history(struct browser_window *bw)
{
	assert(bw != NULL);

	return bw->history;
}


/* Exported interface, documented in browser.h */
bool browser_window_has_content(struct browser_window *bw)
{
	assert(bw != NULL);

	if (bw->current_content == NULL) {
		return false;
	}

	return true;
}

/* Exported interface, documented in browser.h */
struct hlcache_handle *browser_window_get_content(struct browser_window *bw)
{
	return bw->current_content;
}

/* Exported interface, documented in browser.h */
nserror browser_window_get_extents(struct browser_window *bw, bool scaled,
		int *width, int *height)
{
	assert(bw != NULL);

	if (bw->current_content == NULL) {
		*width = 0;
		*height = 0;
		return NSERROR_BAD_CONTENT;
	}

	*width = content_get_width(bw->current_content);
	*height = content_get_height(bw->current_content);

	if (scaled) {
		*width *= bw->scale;
		*height *= bw->scale;
	}

	return NSERROR_OK;
}


/* exported internal interface, documented in desktop/browser_private.h */
void browser_window_get_dimensions(struct browser_window *bw,
		int *width, int *height, bool scaled)
{
	assert(bw);

	if (bw->window == NULL) {
		/* Core managed browser window */
		*width = bw->width;
		*height = bw->height;
	} else {
		/* Front end window */
		guit->window->get_dimensions(bw->window, width, height, scaled);
	}
}


/* Exported interface, documented in browser.h */
void browser_window_set_dimensions(struct browser_window *bw,
		int width, int height)
{
	assert(bw);

	if (bw->window == NULL) {
		/* Core managed browser window */
		bw->width = width;
		bw->height = height;
	} else {
		LOG("Asked to set dimensions of front end window.");
		assert(0);
	}
}


/* Exported interface, documented in browser.h */
void browser_window_update(struct browser_window *bw, bool scroll_to_top)
{
	int x, y;

	if (bw->current_content == NULL)
		return;

	switch (bw->browser_window_type) {

	case BROWSER_WINDOW_NORMAL:
		/* Root browser window, constituting a front end window/tab */
		guit->window->set_title(bw->window,
				content_get_title(bw->current_content));

		browser_window_update_extent(bw);

		if (scroll_to_top)
			browser_window_set_scroll(bw, 0, 0);

		/* if frag_id exists, then try to scroll to it */
		/** @todo don't do this if the user has scrolled */
		if (bw->frag_id && html_get_id_offset(bw->current_content,
				bw->frag_id, &x, &y)) {
			browser_window_set_scroll(bw, x, y);
		}

		guit->window->redraw(bw->window);

		break;

	case BROWSER_WINDOW_IFRAME:
		/* Internal iframe browser window */
		assert(bw->parent != NULL);
		assert(bw->parent->current_content != NULL);

		browser_window_update_extent(bw);

		if (scroll_to_top)
			browser_window_set_scroll(bw, 0, 0);

		/* if frag_id exists, then try to scroll to it */
		/** @todo don't do this if the user has scrolled */
		if (bw->frag_id && html_get_id_offset(bw->current_content,
				bw->frag_id, &x, &y)) {
			browser_window_set_scroll(bw, x, y);
		}

		html_redraw_a_box(bw->parent->current_content, bw->box);
		break;

	case BROWSER_WINDOW_FRAME:
	{
		struct rect rect;
		browser_window_update_extent(bw);

		if (scroll_to_top)
			browser_window_set_scroll(bw, 0, 0);

		/* if frag_id exists, then try to scroll to it */
		/** @todo don't do this if the user has scrolled */
		if (bw->frag_id && html_get_id_offset(bw->current_content,
				bw->frag_id, &x, &y)) {
			browser_window_set_scroll(bw, x, y);
		}

		rect.x0 = scrollbar_get_offset(bw->scroll_x);
		rect.y0 = scrollbar_get_offset(bw->scroll_y);
		rect.x1 = rect.x0 + bw->width;
		rect.y1 = rect.y0 + bw->height;

		browser_window_update_box(bw, &rect);
	}
		break;

	default:
	case BROWSER_WINDOW_FRAMESET:
		/* Nothing to do */
		break;
	}
}

/* Exported interface, documented in netsurf/browser_window.h */
void browser_window_update_box(struct browser_window *bw, struct rect *rect)
{
	int pos_x;
	int pos_y;
	struct browser_window *top;

	assert(bw);

	if (bw->window != NULL) {
		/* Front end window */
		guit->window->update(bw->window, rect);
	} else {
		/* Core managed browser window */
		browser_window_get_position(bw, true, &pos_x, &pos_y);

		top = browser_window_get_root(bw);

		rect->x0 += pos_x / bw->scale;
		rect->y0 += pos_y / bw->scale;
		rect->x1 += pos_x / bw->scale;
		rect->y1 += pos_y / bw->scale;

		guit->window->update(top->window, rect);
	}
}

/* Exported interface, documented in netsurf/browser_window.h */
void browser_window_stop(struct browser_window *bw)
{
	int children, index;

	if (bw->loading_content != NULL) {
		hlcache_handle_abort(bw->loading_content);
		hlcache_handle_release(bw->loading_content);
		bw->loading_content = NULL;
	}

	if (bw->current_content != NULL && content_get_status(
			bw->current_content) != CONTENT_STATUS_DONE) {
		nserror error;
		assert(content_get_status(bw->current_content) ==
				CONTENT_STATUS_READY);
		error = hlcache_handle_abort(bw->current_content);
		assert(error == NSERROR_OK);
	}

	guit->misc->schedule(-1, browser_window_refresh, bw);

	if (bw->children) {
		children = bw->rows * bw->cols;
		for (index = 0; index < children; index++)
			browser_window_stop(&bw->children[index]);
	}
	if (bw->iframes) {
		children = bw->iframe_count;
		for (index = 0; index < children; index++)
			browser_window_stop(&bw->iframes[index]);
	}

	if (bw->current_content != NULL) {
		browser_window_refresh_url_bar(bw);
	}

	browser_window_stop_throbber(bw);
}


/* Exported interface, documented in netsurf/browser_window.h */
void browser_window_reload(struct browser_window *bw, bool all)
{
	hlcache_handle *c;
	unsigned int i;

	if (bw->current_content == NULL || bw->loading_content != NULL)
		return;

	if (all && content_get_type(bw->current_content) == CONTENT_HTML) {
		struct html_stylesheet *sheets;
		struct content_html_object *object;
		unsigned int count;

		c = bw->current_content;

		/* invalidate objects */
		object = html_get_objects(c, &count);

		for (; object != NULL; object = object->next) {
			if (object->content != NULL)
				content_invalidate_reuse_data(object->content);
		}

		/* invalidate stylesheets */
		sheets = html_get_stylesheets(c, &count);

		for (i = STYLESHEET_START; i != count; i++) {
			if (sheets[i].sheet != NULL) {
				content_invalidate_reuse_data(sheets[i].sheet);
			}
		}
	}

	content_invalidate_reuse_data(bw->current_content);

	browser_window_navigate(bw,
				hlcache_handle_get_url(bw->current_content),
				NULL,
				BW_NAVIGATE_NONE,
				NULL,
				NULL,
				NULL);
}


/* Exported interface, documented in netsurf/browser_window.h */
void browser_window_set_status(struct browser_window *bw, const char *text)
{
	int text_len;
	/* find topmost window */
	while (bw->parent)
		bw = bw->parent;

	if ((bw->status_text != NULL) &&
	    (strcmp(text, bw->status_text) == 0)) {
		/* status text is unchanged */
		bw->status_match++;
		return;
	}

	/* status text is changed */

	text_len = strlen(text);

	if ((bw->status_text == NULL) || (bw->status_text_len < text_len)) {
		/* no current string allocation or it is not long enough */
		free(bw->status_text);
		bw->status_text = strdup(text);
		bw->status_text_len = text_len;
	} else {
		/* current allocation has enough space */
		memcpy(bw->status_text, text, text_len + 1);
	}

	bw->status_miss++;
	guit->window->set_status(bw->window, bw->status_text);
}


/* Exported interface, documented in netsurf/browser_window.h */
void browser_window_set_pointer(struct browser_window *bw,
		browser_pointer_shape shape)
{
	struct browser_window *root = browser_window_get_root(bw);
	gui_pointer_shape gui_shape;
	bool loading;
	uint64_t ms_now;

	assert(root);
	assert(root->window);

	loading = ((bw->loading_content != NULL) ||
		   ((bw->current_content != NULL) &&
		    (content_get_status(bw->current_content) == CONTENT_STATUS_READY)));

	nsu_getmonotonic_ms(&ms_now);

	if (loading && ((ms_now - bw->last_action) < 1000)) {
		/* If loading and less than 1 second since last link followed,
		 * force progress indicator pointer */
		gui_shape = GUI_POINTER_PROGRESS;

	} else if (shape == BROWSER_POINTER_AUTO) {
		/* Up to browser window to decide */
		if (loading) {
			gui_shape = GUI_POINTER_PROGRESS;
		} else {
			gui_shape = GUI_POINTER_DEFAULT;
		}

	} else {
		/* Use what we were told */
		gui_shape = (gui_pointer_shape)shape;
	}

	guit->window->set_pointer(root->window, gui_shape);
}

/* exported function documented in netsurf/browser_window.h */
nserror browser_window_schedule_reformat(struct browser_window *bw)
{
	/* The ugly cast here is so the reformat function can be
	 * passed a gui window pointer in its API rather than void*
	 */
	guit->misc->schedule(0, (void(*)(void*))guit->window->reformat, bw->window);
	return NSERROR_OK;
}


/* exported function documented in netsurf/browser_window.h */
void browser_window_reformat(struct browser_window *bw, bool background,
		int width, int height)
{
	hlcache_handle *c = bw->current_content;

	if (c == NULL)
		return;

	if (bw->browser_window_type != BROWSER_WINDOW_IFRAME) {
		/* Iframe dimensions are already scaled in parent's layout */
		width  /= bw->scale;
		height /= bw->scale;
	}

	if (bw->window == NULL) {
		/* Core managed browser window; subtract scrollbar width */
		width  -= bw->scroll_y ? SCROLLBAR_WIDTH : 0;
		height -= bw->scroll_x ? SCROLLBAR_WIDTH : 0;

		width  = width  > 0 ? width  : 0;
		height = height > 0 ? height : 0;
	}

	content_reformat(c, background, width, height);
}

/**
 * Set browser window scale.
 *
 * \param bw Browser window.
 * \param scale value.
 */
static void browser_window_set_scale_internal(struct browser_window *bw,
		float scale)
{
	int i;
	hlcache_handle *c;

	if (fabs(bw->scale-scale) < 0.0001)
		return;

	bw->scale = scale;
	c = bw->current_content;

	if (c != NULL) {
		if (content_can_reformat(c) == false) {
			browser_window_update(bw, false);
		} else {
			browser_window_schedule_reformat(bw);
		}
	}

	for (i = 0; i < (bw->cols * bw->rows); i++)
		browser_window_set_scale_internal(&bw->children[i], scale);
	for (i = 0; i < bw->iframe_count; i++)
		browser_window_set_scale_internal(&bw->iframes[i], scale);
}


/* exported interface documented in netsurf/browser_window.h */
void browser_window_set_scale(struct browser_window *bw, float scale, bool all)
{
	while (bw->parent && all)
		bw = bw->parent;

	browser_window_set_scale_internal(bw, scale);

	if (bw->parent)
		bw = bw->parent;

	browser_window_recalculate_frameset(bw);
}


/* exported interface documented in netsurf/browser_window.h */
float browser_window_get_scale(struct browser_window *bw)
{
	if (bw == NULL) {
		return 1.0;
	}

	return bw->scale;
}

/**
 * Find browser window.
 *
 * \param bw Browser window.
 * \param target Name of target.
 * \param depth Depth to scan.
 * \param page The browser window page.
 * \param rdepth The rdepth.
 * \param bw_target the output browser window.
 */
static void browser_window_find_target_internal(struct browser_window *bw,
		const char *target, int depth, struct browser_window *page,
		int *rdepth, struct browser_window **bw_target)
{
	int i;

	if ((bw->name) && (!strcasecmp(bw->name, target))) {
		if ((bw == page) || (depth > *rdepth)) {
			*rdepth = depth;
			*bw_target = bw;
		}
	}

	if ((!bw->children) && (!bw->iframes))
		return;

	depth++;

	if (bw->children != NULL) {
		for (i = 0; i < (bw->cols * bw->rows); i++) {
			if ((bw->children[i].name) &&
					(!strcasecmp(bw->children[i].name,
					target))) {
				if ((page == &bw->children[i]) ||
						(depth > *rdepth)) {
					*rdepth = depth;
					*bw_target = &bw->children[i];
				}
			}
			if (bw->children[i].children)
				browser_window_find_target_internal(
						&bw->children[i],
						target, depth, page,
						rdepth, bw_target);
		}
	}

	if (bw->iframes != NULL) {
		for (i = 0; i < bw->iframe_count; i++)
			browser_window_find_target_internal(&bw->iframes[i],
					target, depth, page, rdepth, bw_target);
	}
}


/* exported interface documented in netsurf/browser_window.h */
struct browser_window *browser_window_find_target(struct browser_window *bw,
		const char *target, browser_mouse_state mouse)
{
	struct browser_window *bw_target;
	struct browser_window *top;
	hlcache_handle *c;
	int rdepth;
	nserror error;

	/* use the base target if we don't have one */
	c = bw->current_content;
	if (target == NULL && c != NULL && content_get_type(c) == CONTENT_HTML)
		target = html_get_base_target(c);
	if (target == NULL)
		target = TARGET_SELF;

	/* allow the simple case of target="_blank" to be ignored if requested
	 */
	if ((!(mouse & BROWSER_MOUSE_CLICK_2)) &&
			(!((mouse & BROWSER_MOUSE_CLICK_2) &&
			(mouse & BROWSER_MOUSE_MOD_2))) &&
	    (!nsoption_bool(target_blank))) {
		/* not a mouse button 2 click
		 * not a mouse button 1 click with ctrl pressed
		 * configured to ignore target="_blank" */
		if ((target == TARGET_BLANK) || (!strcasecmp(target, "_blank")))
			return bw;
	}

	/* handle reserved keywords */
	if (((nsoption_bool(button_2_tab)) &&
	     (mouse & BROWSER_MOUSE_CLICK_2))||
	    ((!nsoption_bool(button_2_tab)) &&
	     ((mouse & BROWSER_MOUSE_CLICK_1) &&
	      (mouse & BROWSER_MOUSE_MOD_2))) ||
	    ((nsoption_bool(button_2_tab)) &&
	     ((target == TARGET_BLANK) ||
	      (!strcasecmp(target, "_blank"))))) {
		/* open in new tab if:
		 * - button_2 opens in new tab and button_2 was pressed
		 * OR
		 * - button_2 doesn't open in new tabs and button_1 was
		 *   pressed with ctrl held
		 * OR
		 * - button_2 opens in new tab and the link target is "_blank"
		 */
		error = browser_window_create(BW_CREATE_TAB |
					      BW_CREATE_HISTORY |
					      BW_CREATE_CLONE,
					      NULL,
					      NULL,
					      bw,
					      &bw_target);
		if (error != NSERROR_OK) {
			return bw;
		}
		return bw_target;
	} else if (((!nsoption_bool(button_2_tab)) &&
		    (mouse & BROWSER_MOUSE_CLICK_2)) ||
		   ((nsoption_bool(button_2_tab)) &&
		    ((mouse & BROWSER_MOUSE_CLICK_1) &&
		     (mouse & BROWSER_MOUSE_MOD_2))) ||
		   ((!nsoption_bool(button_2_tab)) &&
		    ((target == TARGET_BLANK) ||
		     (!strcasecmp(target, "_blank"))))) {
		/* open in new window if:
		 * - button_2 doesn't open in new tabs and button_2 was pressed
		 * OR
		 * - button_2 opens in new tab and button_1 was pressed with
		 *   ctrl held
		 * OR
		 * - button_2 doesn't open in new tabs and the link target is
		 *   "_blank"
		 */
		error = browser_window_create(BW_CREATE_HISTORY |
					      BW_CREATE_CLONE,
					      NULL,
					      NULL,
					      bw,
					      &bw_target);
		if (error != NSERROR_OK) {
			return bw;
		}
		return bw_target;
	} else if ((target == TARGET_SELF) || (!strcasecmp(target, "_self"))) {
		return bw;
	} else if ((target == TARGET_PARENT) ||
			(!strcasecmp(target, "_parent"))) {
		if (bw->parent)
			return bw->parent;
		return bw;
	} else if ((target == TARGET_TOP) || (!strcasecmp(target, "_top"))) {
		while (bw->parent)
			bw = bw->parent;
		return bw;
	}

	/* find frame according to B.8, ie using the following priorities:
	 *
	 *  1) current frame
	 *  2) closest to front
	 */
	rdepth = -1;
	bw_target = NULL;
	for (top = bw; top->parent; top = top->parent);
	browser_window_find_target_internal(top, target, 0, bw, &rdepth,
			&bw_target);
	if (bw_target)
		return bw_target;

	/* we require a new window using the target name */
	if (!nsoption_bool(target_blank))
		return bw;

	error = browser_window_create(BW_CREATE_CLONE | BW_CREATE_HISTORY,
				      NULL,
				      NULL,
				      bw,
				      &bw_target);
	if (error != NSERROR_OK) {
		return bw;
	}

	/* frame names should begin with an alphabetic character (a-z,A-Z),
	 * however in practice you get things such as '_new' and '2left'. The
	 * only real effect this has is when giving out names as it can be
	 * assumed that an author intended '_new' to create a new nameless
	 * window (ie '_blank') whereas in the case of '2left' the intention
	 * was for a new named window. As such we merely special case windows
	 * that begin with an underscore. */
	if (target[0] != '_') {
		bw_target->name = strdup(target);
		if (!bw_target->name)
			guit->misc->warning("NoMemory", NULL);
	}
	return bw_target;
}


/**
 * Handles the end of a drag operation in a browser window.
 *
 * \param  bw	  browser window
 * \param  mouse  state of mouse buttons and modifier keys
 * \param  x	  coordinate of mouse
 * \param  y	  coordinate of mouse
 *
 * \todo Remove this function, once these things are associated with content,
 *       rather than bw.
 */
static void browser_window_mouse_drag_end(struct browser_window *bw,
		browser_mouse_state mouse, int x, int y)
{
	int scr_x, scr_y;

	switch (bw->drag_type) {
	case DRAGGING_SELECTION:
	case DRAGGING_OTHER:
	case DRAGGING_CONTENT_SCROLLBAR:
		/* Drag handled by content handler */
		break;

	case DRAGGING_SCR_X:

		browser_window_get_scrollbar_pos(bw, true, &scr_x, &scr_y);

		scr_x = x - scr_x - scrollbar_get_offset(bw->scroll_x);
		scr_y = y - scr_y - scrollbar_get_offset(bw->scroll_y);

		scrollbar_mouse_drag_end(bw->scroll_x, mouse, scr_x, scr_y);

		bw->drag_type = DRAGGING_NONE;
		break;

	case DRAGGING_SCR_Y:

		browser_window_get_scrollbar_pos(bw, false, &scr_x, &scr_y);

		scr_x = x - scr_x - scrollbar_get_offset(bw->scroll_x);
		scr_y = y - scr_y - scrollbar_get_offset(bw->scroll_y);

		scrollbar_mouse_drag_end(bw->scroll_y, mouse, scr_x, scr_y);

		bw->drag_type = DRAGGING_NONE;
		break;

	default:
		browser_window_set_drag_type(bw, DRAGGING_NONE, NULL);
		break;
	}
}


/* exported interface documented in netsurf/browser_window.h */
void browser_window_mouse_track(struct browser_window *bw,
		browser_mouse_state mouse, int x, int y)
{
	hlcache_handle *c = bw->current_content;
	const char *status = NULL;
	browser_pointer_shape pointer = BROWSER_POINTER_DEFAULT;

	if (bw->window != NULL && bw->drag_window && bw != bw->drag_window) {
		/* This is the root browser window and there's an active drag
		 * in a sub window.
		 * Pass the mouse action straight on to that bw. */
		struct browser_window *drag_bw = bw->drag_window;
		int off_x = 0;
		int off_y = 0;

		browser_window_get_position(drag_bw, true, &off_x, &off_y);

		if (drag_bw->browser_window_type == BROWSER_WINDOW_FRAME) {
			browser_window_mouse_track(drag_bw, mouse,
					x - off_x, y - off_y);

		} else if (drag_bw->browser_window_type ==
				BROWSER_WINDOW_IFRAME) {
			browser_window_mouse_track(drag_bw, mouse,
					x - off_x / bw->scale,
					y - off_y / bw->scale);
		}
		return;
	}

	if (bw->children) {
		/* Browser window has children (frames) */
		struct browser_window *child;
		int cur_child;
		int children = bw->rows * bw->cols;

		for (cur_child = 0; cur_child < children; cur_child++) {

			child = &bw->children[cur_child];

			if (x < child->x || y < child->y ||
					child->x + child->width < x ||
					child->y + child->height < y) {
				/* Click not in this child */
				continue;
			}

			/* It's this child that contains the mouse; pass
			 * mouse action on to child */
			browser_window_mouse_track(child, mouse,
					x - child->x + scrollbar_get_offset(
							child->scroll_x),
					y - child->y + scrollbar_get_offset(
							child->scroll_y));

			/* Mouse action was for this child, we're done */
			return;
		}

		/* Odd if we reached here, but nothing else can use the click
		 * when there are children. */
		return;
	}

	if (c == NULL && bw->drag_type != DRAGGING_FRAME)
		return;

	if (bw->drag_type != DRAGGING_NONE && !mouse) {
		browser_window_mouse_drag_end(bw, mouse, x, y);
	}

	/* Browser window's horizontal scrollbar */
	if (bw->scroll_x != NULL && bw->drag_type != DRAGGING_SCR_Y) {
		int scr_x, scr_y;
		browser_window_get_scrollbar_pos(bw, true, &scr_x, &scr_y);
		scr_x = x - scr_x - scrollbar_get_offset(bw->scroll_x);
		scr_y = y - scr_y - scrollbar_get_offset(bw->scroll_y);

		if ((scr_x > 0 && scr_x < browser_window_get_scrollbar_len(bw,
						true) &&
				scr_y > 0 && scr_y < SCROLLBAR_WIDTH &&
				bw->drag_type == DRAGGING_NONE) ||
				bw->drag_type == DRAGGING_SCR_X) {
			/* Start a scrollbar drag, or continue existing drag */
			status = scrollbar_mouse_status_to_message(
					scrollbar_mouse_action(
							bw->scroll_x, mouse,
							scr_x, scr_y));
			pointer = BROWSER_POINTER_DEFAULT;

			if (status != NULL)
				browser_window_set_status(bw, status);

			browser_window_set_pointer(bw, pointer);
			return;
		}
	}

	/* Browser window's vertical scrollbar */
	if (bw->scroll_y != NULL) {
		int scr_x, scr_y;
		browser_window_get_scrollbar_pos(bw, false, &scr_x, &scr_y);
		scr_x = x - scr_x - scrollbar_get_offset(bw->scroll_x);
		scr_y = y - scr_y - scrollbar_get_offset(bw->scroll_y);

		if ((scr_y > 0 && scr_y < browser_window_get_scrollbar_len(bw,
						false) &&
				scr_x > 0 && scr_x < SCROLLBAR_WIDTH &&
				bw->drag_type == DRAGGING_NONE) ||
				bw->drag_type == DRAGGING_SCR_Y) {
			/* Start a scrollbar drag, or continue existing drag */
			status = scrollbar_mouse_status_to_message(
					scrollbar_mouse_action(
							bw->scroll_y, mouse,
							scr_x, scr_y));
			pointer = BROWSER_POINTER_DEFAULT;

			if (status != NULL)
				browser_window_set_status(bw, status);

			browser_window_set_pointer(bw, pointer);
			return;
		}
	}

	if (bw->drag_type == DRAGGING_FRAME) {
		browser_window_resize_frame(bw, bw->x + x, bw->y + y);
	} else if (bw->drag_type == DRAGGING_PAGE_SCROLL) {
		/* mouse movement since drag started */
		int scrollx = bw->drag_start_x - x;
		int scrolly = bw->drag_start_y - y;

		/* new scroll offsets */
		scrollx += bw->drag_start_scroll_x;
		scrolly += bw->drag_start_scroll_y;

		bw->drag_start_scroll_x = scrollx;
		bw->drag_start_scroll_y = scrolly;

		browser_window_set_scroll(bw, scrollx, scrolly);
	} else {
		assert(c != NULL);
		content_mouse_track(c, bw, mouse, x, y);
	}
}


/* exported interface documented in netsurf/browser_window.h */
void browser_window_mouse_click(struct browser_window *bw,
		browser_mouse_state mouse, int x, int y)
{
	hlcache_handle *c = bw->current_content;
	const char *status = NULL;
	browser_pointer_shape pointer = BROWSER_POINTER_DEFAULT;

	if (bw->children) {
		/* Browser window has children (frames) */
		struct browser_window *child;
		int cur_child;
		int children = bw->rows * bw->cols;

		for (cur_child = 0; cur_child < children; cur_child++) {

			child = &bw->children[cur_child];

			if (x < child->x || y < child->y ||
					child->x + child->width < x ||
					child->y + child->height < y) {
				/* Click not in this child */
				continue;
			}

			/* It's this child that contains the click; pass it
			 * on to child. */
			browser_window_mouse_click(child, mouse,
					x - child->x + scrollbar_get_offset(
							child->scroll_x),
					y - child->y + scrollbar_get_offset(
							child->scroll_y));

			/* Mouse action was for this child, we're done */
			return;
		}

		return;
	}

	if (!c)
		return;

	if (bw->scroll_x != NULL) {
		int scr_x, scr_y;
		browser_window_get_scrollbar_pos(bw, true, &scr_x, &scr_y);
		scr_x = x - scr_x - scrollbar_get_offset(bw->scroll_x);
		scr_y = y - scr_y - scrollbar_get_offset(bw->scroll_y);

		if (scr_x > 0 && scr_x < browser_window_get_scrollbar_len(bw,
						true) &&
				scr_y > 0 && scr_y < SCROLLBAR_WIDTH) {
			status = scrollbar_mouse_status_to_message(
					scrollbar_mouse_action(
							bw->scroll_x, mouse,
							scr_x, scr_y));
			pointer = BROWSER_POINTER_DEFAULT;

			if (status != NULL)
				browser_window_set_status(bw, status);

			browser_window_set_pointer(bw, pointer);
			return;
		}
	}

	if (bw->scroll_y != NULL) {
		int scr_x, scr_y;
		browser_window_get_scrollbar_pos(bw, false, &scr_x, &scr_y);
		scr_x = x - scr_x - scrollbar_get_offset(bw->scroll_x);
		scr_y = y - scr_y - scrollbar_get_offset(bw->scroll_y);

		if (scr_y > 0 && scr_y < browser_window_get_scrollbar_len(bw,
						false) &&
				scr_x > 0 && scr_x < SCROLLBAR_WIDTH) {
			status = scrollbar_mouse_status_to_message(
					scrollbar_mouse_action(
							bw->scroll_y, mouse,
							scr_x, scr_y));
			pointer = BROWSER_POINTER_DEFAULT;

			if (status != NULL)
				browser_window_set_status(bw, status);

			browser_window_set_pointer(bw, pointer);
			return;
		}
	}

	switch (content_get_type(c)) {
	case CONTENT_HTML:
	case CONTENT_TEXTPLAIN:
	{
		/* Give bw focus */
		struct browser_window *root_bw = browser_window_get_root(bw);
		if (bw != root_bw->focus) {
			browser_window_remove_caret(bw, false);
			browser_window_set_selection(bw, false, true);
			root_bw->focus = bw;
		}

		/* Pass mouse action to content */
		content_mouse_action(c, bw, mouse, x, y);
	}
		break;
	default:
		if (mouse & BROWSER_MOUSE_MOD_2) {
			if (mouse & BROWSER_MOUSE_DRAG_2) {
				guit->window->drag_save_object(bw->window, c,
						GUI_SAVE_OBJECT_NATIVE);
			} else if (mouse & BROWSER_MOUSE_DRAG_1) {
				guit->window->drag_save_object(bw->window, c,
						GUI_SAVE_OBJECT_ORIG);
			}
		} else if (mouse & (BROWSER_MOUSE_DRAG_1 |
				BROWSER_MOUSE_DRAG_2)) {
			browser_window_page_drag_start(bw, x, y);
			browser_window_set_pointer(bw, BROWSER_POINTER_MOVE);
		}
		break;
	}
}



/* exported interface documented in netsurf/browser_window.h */
void browser_window_redraw_rect(struct browser_window *bw, int x, int y,
		int width, int height)
{
	content_request_redraw(bw->current_content, x, y, width, height);
}


/* exported interface documented in netsurf/browser_window.h */
void browser_window_page_drag_start(struct browser_window *bw, int x, int y)
{
	assert(bw != NULL);

	browser_window_set_drag_type(bw, DRAGGING_PAGE_SCROLL, NULL);

	bw->drag_start_x = x;
	bw->drag_start_y = y;

	if (bw->window != NULL) {
		/* Front end window */
		guit->window->get_scroll(bw->window, &bw->drag_start_scroll_x,
				&bw->drag_start_scroll_y);

		guit->window->scroll_start(bw->window);
	} else {
		/* Core managed browser window */
		bw->drag_start_scroll_x = scrollbar_get_offset(bw->scroll_x);
		bw->drag_start_scroll_y = scrollbar_get_offset(bw->scroll_y);
	}
}



/* exported interface documented in netsurf/browser_window.h */
bool browser_window_back_available(struct browser_window *bw)
{
	return (bw && bw->history &&
			browser_window_history_back_available(bw));
}



/* exported interface documented in netsurf/browser_window.h */
bool browser_window_forward_available(struct browser_window *bw)
{
	return (bw && bw->history &&
			browser_window_history_forward_available(bw));
}

/* exported interface documented in netsurf/browser_window.h */
bool browser_window_reload_available(struct browser_window *bw)
{
	return (bw && bw->current_content && !bw->loading_content);
}


/* exported interface documented in netsurf/browser_window.h */
bool browser_window_stop_available(struct browser_window *bw)
{
	return (bw && (bw->loading_content ||
			(bw->current_content &&
			(content_get_status(bw->current_content) !=
			CONTENT_STATUS_DONE))));
}

/* exported interface documented in browser.h */
nserror browser_set_dpi(int dpi)
{
	nscss_screen_dpi = INTTOFIX(dpi);

	return NSERROR_OK;
}

/* exported interface documented in browser.h */
int browser_get_dpi(void)
{
	return FIXTOINT(nscss_screen_dpi);
}